Room and Organ Acoustic Measurements of St. Jakobus Church Ilmenau - Part 2: Spatial Room Impulse Responses

This is part of a dataset of organ recordings and room acoustic measurements of St. Jakobus Church, Ilmenau. For an overview of the complete dataset, please refer to Room and Organ Acoustic Measurements of St. Jakobus Church Ilmenau.

This dataset is an collection of Spatial Room Impulse Responses (SRIRs) for multiple source receiver combinations in the church. The zip files contain SOFA files that contain all the data like the SRIRs themselfs, source and receiver positions, and other metadata. The files follow SOFA (v. 2.1) convention SingleRoomSRIR 1.1 in accordance with AES69-2022.

Microphone arrays based on Erathworks M30 microphones in the center with 6 electret capsules spherically distributed around that were used as receivers. The design of the arrays follows the recommendation of Optimizations of the Spatial Decomposition Method for Binaural Reproduction, for the measured RIRs to be used with the Spatial Decomposition Method for binaural rendering. 
With a binaural reproduction in AR/VR with a free moving user in mind, a grid of positions on the ground floor was measured. 
For that, a robotic platform equipped with the microphone array and approached 37 positions in the nave. 
This includes positions between the pews, underneath the galleries and the organ and behind columns. 

The rear section of the church, beneath the gallery where the organ is located, can be separated by a movable glass wall.
The RIR measurement swith the robot were performed once without and once with this glass wall installed.
When churches are converted for other uses, parts of the building may be structurally separated from one another.
In this case, the glass wall is intended to simulate such a change, or at least provide an indication of how something like this would affect the acoustics. ROAM-JIL-Open.zip containes the measurments without the glass wall, ROAM-JIL-Closed.zip the ones with the glass wall installed.

Additionally, three measurements on each of the two levels of galleries where conducted by hand above the middle of the nave. These measurements are in ROAM-JIL-Gallery.zip.

A subwoofer and two loudspeakers were positioned as close as possible at the mouths of the facade pipes without risking damage to the organ.  To mimic the pipes radiation pattern, directional studio monitors (Genelec 7360A and 8341A ) where chosen.  On the opposite side of the church, in front of the altar, an omnidirectional source (Outline GSR Speaker and Subwoofer) was placed in order to have a significantly different place of excitation and to be able to perform room acoustic analyses in the classical sense.

Exponetial Sine Sweeps with a length of 15 s and 4 s of decay time were used as excitation signal. For the Genelec Subwoofer, the signal ranged from 18 Hz - 1 kHz, for all other loudspeakers from 20 Hz - 22 kHz.